In Vitro Osteogenic Stimulation of Human Adipose-Derived MSCs on Biofunctional 3D-Printed Scaffolds

Background: Human adipose-derived mesenchymal stem cells (hADMSCs) are widely used in regenerative medicine due to their ability to proliferate and differentiate. Bone tissue engineering represents an innovative alternative to traditional grafts by combining biomimetic materials, stem cells, and bioactive factors to promote bone regeneration. Gellan gum (GG) is a promising scaffold material owing to its excellent biocompatibility and favorable physicochemical characteristics; however, chemical modifications such as methacrylation are necessary to enhance its mechanical strength and long-term stability. In this in vitro study, osteoprogenitor cells are cultured for 21 days on three 3D-printed GGMA-based scaffolds to evaluate their biological response: (i) neat GGMA, (ii) GGMA functionalized with hydroxyapatite (HAp), and (iii) GGMA functionalized with eumelanin derived from black soldier fly (BSF-Eumelanin). Methods: Cell adhesion, viability, proliferation and osteogenic differentiation are evaluated using MTT assays, histological staining (H&E and Alizarin Red S), alkaline phosphatase (ALP) activity, and gene expression analysis of key osteogenic markers. Results: Our results show that all GGMA-based scaffolds support cell adhesion, growth, and proliferation, while BSF-Eumelanin and HAp notably enhance osteogenic differentiation compared to neat GGMA. Conclusions: These findings highlight the potential of embedding bioactive factors into GGMA scaffolds to improve osteoconductive and osteoinductive performance, offering a promising strategy for bone repair.